The present invention relates to a tool for the infusion of a resin into a preform made of fibre material, the tool comprising a mould which can be closed around the preform and in the body of which at least one inlet duct is formed to allow resin to be injected into the mould so the resin can be infused into the preform.
The need to reduce weight and to eliminate problems of corrosion of aeronautical structures has led the industry to construct commercial aircraft fuselages from composite material.
Amongst the structural elements which make up the fuselage, there are some which, in the current state of the art, are made of light alloy. The use of such metal elements in contact with the composite structure leads to galvanic coupling problems with risks of metal corrosion and necessitates increased inspection levels, along with the related costs to the airlines.
A need has therefore arisen to make those components that are typically designed and constructed of metal also of composite material, overcoming some material and process problems such as:                highly accurate control of the surfaces for interfacing with other fuselage parts,        fibre orientation, which is often polar and not Cartesian,        fire resistance requirements with limited release of smoke and other toxic elements.        
Currently, the technology would enable such components to be made of pre-impregnated materials but that does not allow for curved orientation of the fibres; or else, it would permit the use of the “resin transfer moulding” (RTM) process which enables dry carbon fibre reinforcing preforms positioned in the curing mould to be infused with resin. This would permit both accurate control of the surfaces and the use of reinforcements with curved fibre orientations.
However, this process has the following structural disadvantage: to permit the flow of resin during the RTM process it is necessary to use highly fluid resins which cannot therefore contain within them the toughening elements that are necessary to improve properties such as compression after impact or low inflammability properties. An alternative is to use resins the toughener of which is woven into the preform and can then be dissolved in the resin upon infusion. However, that process makes the production of the preform more complex and expensive.